Convenient configuration of type permissions for XStream 1.4.18

Closes gh-27343

spring-oxm/src/main/java/org/springframework/oxm/xstream/XStreamMarshaller.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -63,6 +63,8 @@ import com.thoughtworks.xstream.io.xml.XppDriver;
 import com.thoughtworks.xstream.mapper.CannotResolveClassException;
 import com.thoughtworks.xstream.mapper.Mapper;
 import com.thoughtworks.xstream.mapper.MapperWrapper;
+import com.thoughtworks.xstream.security.ForbiddenClassException;
+import com.thoughtworks.xstream.security.TypePermission;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.Node;
@@ -106,7 +108,7 @@ import org.springframework.util.xml.StaxUtils;
  * Therefore, it has limited namespace support. As such, it is rather unsuitable for
  * usage within Web Services.
  *
- * <p>This marshaller requires XStream 1.4.5 or higher, as of Spring 4.3.
+ * <p>This marshaller requires XStream 1.4.7 or higher, as of Spring 5.2.17.
  * Note that {@link XStream} construction has been reworked in 4.0, with the
  * stream driver and the class loader getting passed into XStream itself now.
  *
@@ -146,6 +148,9 @@ public class XStreamMarshaller extends AbstractMarshaller implements BeanClassLo
 	@Nullable
 	private ConverterMatcher[] converters;
 
+	@Nullable
+	private TypePermission[] typePermissions;
+
 	@Nullable
 	private MarshallingStrategy marshallingStrategy;
 
@@ -268,6 +273,20 @@ public class XStreamMarshaller extends AbstractMarshaller implements BeanClassLo
 		this.converters = converters;
 	}
 
+	/**
+	 * Set XStream type permissions such as
+	 * {@link com.thoughtworks.xstream.security.AnyTypePermission},
+	 * {@link com.thoughtworks.xstream.security.ExplicitTypePermission} etc,
+	 * as an alternative to overriding the {@link #customizeXStream} method.
+	 * <p>Note: As of XStream 1.4.18, the default type permissions are
+	 * restricted to well-known core JDK types. For any custom types,
+	 * explicit type permissions need to be registered.
+	 * @since 5.2.17
+	 */
+	public void setTypePermissions(TypePermission... typePermissions) {
+		this.typePermissions = typePermissions;
+	}
+
 	/**
 	 * Set a custom XStream {@link MarshallingStrategy} to use.
 	 * @since 4.0
@@ -407,7 +426,7 @@ public class XStreamMarshaller extends AbstractMarshaller implements BeanClassLo
 
 	@Override
 	public void afterPropertiesSet() {
-		// no-op due to use of SingletonSupplier for the XStream field.
+		// no-op due to use of SingletonSupplier for the XStream field
 	}
 
 	/**
@@ -479,6 +498,12 @@ public class XStreamMarshaller extends AbstractMarshaller implements BeanClassLo
 			}
 		}
 
+		if (this.typePermissions != null) {
+			for (TypePermission permission : this.typePermissions) {
+				xstream.addPermission(permission);
+			}
+		}
+
 		if (this.marshallingStrategy != null) {
 			xstream.setMarshallingStrategy(this.marshallingStrategy);
 		}
@@ -844,7 +869,7 @@ public class XStreamMarshaller extends AbstractMarshaller implements BeanClassLo
 	 */
 	protected XmlMappingException convertXStreamException(Exception ex, boolean marshalling) {
 		if (ex instanceof StreamException || ex instanceof CannotResolveClassException ||
-				ex instanceof ConversionException) {
+				ex instanceof ForbiddenClassException || ex instanceof ConversionException) {
 			if (marshalling) {
 				return new MarshallingFailureException("XStream marshalling exception",  ex);
 			}

spring-oxm/src/test/java/org/springframework/oxm/xstream/XStreamMarshallerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -43,6 +43,7 @@ import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
 import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver;
 import com.thoughtworks.xstream.io.json.JsonHierarchicalStreamDriver;
 import com.thoughtworks.xstream.io.json.JsonWriter;
+import com.thoughtworks.xstream.security.AnyTypePermission;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.mockito.InOrder;
@@ -67,18 +68,21 @@ import static org.mockito.Mockito.mock;
 /**
  * @author Arjen Poutsma
  * @author Sam Brannen
+ * @author Juergen Hoeller
  */
 class XStreamMarshallerTests {
 
 	private static final String EXPECTED_STRING = "<flight><flightNumber>42</flightNumber></flight>";
 
-	private final XStreamMarshaller marshaller = new XStreamMarshaller();
-
 	private final Flight flight = new Flight();
 
+	private XStreamMarshaller marshaller;
+
 
 	@BeforeEach
 	void createMarshaller() {
+		marshaller = new XStreamMarshaller();
+		marshaller.setTypePermissions(AnyTypePermission.ANY);
 		marshaller.setAliases(Collections.singletonMap("flight", Flight.class.getName()));
 		flight.setFlightNumber(42L);
 	}
@@ -143,7 +147,7 @@ class XStreamMarshallerTests {
 		ByteArrayOutputStream os = new ByteArrayOutputStream();
 		StreamResult result = new StreamResult(os);
 		marshaller.marshal(flight, result);
-		String s = new String(os.toByteArray(), "UTF-8");
+		String s = os.toString("UTF-8");
 		assertThat(XmlContent.of(s)).isSimilarTo(EXPECTED_STRING);
 	}
 

spring-oxm/src/test/java/org/springframework/oxm/xstream/XStreamUnmarshallerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@ package org.springframework.oxm.xstream;
 
 import java.io.ByteArrayInputStream;
 import java.io.StringReader;
+import java.nio.charset.StandardCharsets;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -29,6 +30,7 @@ import javax.xml.transform.Source;
 import javax.xml.transform.dom.DOMSource;
 import javax.xml.transform.stream.StreamSource;
 
+import com.thoughtworks.xstream.security.AnyTypePermission;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.w3c.dom.Document;
@@ -40,6 +42,7 @@ import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * @author Arjen Poutsma
+ * @author Juergen Hoeller
  */
 public class XStreamUnmarshallerTests {
 
@@ -47,21 +50,16 @@ public class XStreamUnmarshallerTests {
 
 	private XStreamMarshaller unmarshaller;
 
+
 	@BeforeEach
-	public void createUnmarshaller() throws Exception {
+	public void createUnmarshaller() {
 		unmarshaller = new XStreamMarshaller();
+		unmarshaller.setTypePermissions(AnyTypePermission.ANY);
 		Map<String, Class<?>> aliases = new HashMap<>();
 		aliases.put("flight", Flight.class);
 		unmarshaller.setAliases(aliases);
 	}
 
-	private void testFlight(Object o) {
-		boolean condition = o instanceof Flight;
-		assertThat(condition).as("Unmarshalled object is not Flights").isTrue();
-		Flight flight = (Flight) o;
-		assertThat(flight).as("Flight is null").isNotNull();
-		assertThat(flight.getFlightNumber()).as("Number is invalid").isEqualTo(42L);
-	}
 
 	@Test
 	public void unmarshalDomSource() throws Exception {
@@ -83,7 +81,7 @@ public class XStreamUnmarshallerTests {
 
 	@Test
 	public void unmarshalStreamSourceInputStream() throws Exception {
-		StreamSource source = new StreamSource(new ByteArrayInputStream(INPUT_STRING.getBytes("UTF-8")));
+		StreamSource source = new StreamSource(new ByteArrayInputStream(INPUT_STRING.getBytes(StandardCharsets.UTF_8)));
 		Object flights = unmarshaller.unmarshal(source);
 		testFlight(flights);
 	}
@@ -94,5 +92,15 @@ public class XStreamUnmarshallerTests {
 		Object flights = unmarshaller.unmarshal(source);
 		testFlight(flights);
 	}
+
+
+	private void testFlight(Object o) {
+		boolean condition = o instanceof Flight;
+		assertThat(condition).as("Unmarshalled object is not Flights").isTrue();
+		Flight flight = (Flight) o;
+		assertThat(flight).as("Flight is null").isNotNull();
+		assertThat(flight.getFlightNumber()).as("Number is invalid").isEqualTo(42L);
+	}
+
 }